1; RUN: opt -S -rewrite-statepoints-for-gc %s | FileCheck %s
2
3declare void @foo()
4declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
5
6; constants don't get relocated.
7define i8 @test() gc "statepoint-example" {
8; CHECK-LABEL: @test
9; CHECK: gc.statepoint
10; CHECK-NEXT: load i8, i8 addrspace(1)* inttoptr (i64 15 to i8 addrspace(1)*)
11entry:
12  call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
13  %res = load i8, i8 addrspace(1)* inttoptr (i64 15 to i8 addrspace(1)*)
14  ret i8 %res
15}
16
17
18; Mostly just here to show reasonable code test can come from.
19define i8 @test2(i8 addrspace(1)* %p) gc "statepoint-example" {
20; CHECK-LABEL: @test2
21; CHECK: gc.statepoint
22; CHECK-NEXT: gc.relocate
23; CHECK-NEXT: icmp
24entry:
25  call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
26  %cmp = icmp eq i8 addrspace(1)* %p, null
27  br i1 %cmp, label %taken, label %not_taken
28
29taken:
30  ret i8 0
31
32not_taken:
33  %cmp2 = icmp ne i8 addrspace(1)* %p, null
34  br i1 %cmp2, label %taken, label %dead
35
36dead:
37  ; We see that dead can't be reached, but the optimizer might not.  It's
38  ; completely legal for it to exploit the fact that if dead executed, %p
39  ; would have to equal null.  This can produce intermediate states which
40  ; look like that of test above, even if arbitrary constant addresses aren't
41  ; legal in the source language
42  %addr = getelementptr i8, i8 addrspace(1)* %p, i32 15
43  %res = load i8, i8addrspace(1)* %addr
44  ret i8 %res
45}
46
47@G = addrspace(1) global i8 5
48
49; Globals don't move and thus don't get relocated
50define i8 @test3(i1 %always_true) gc "statepoint-example" {
51; CHECK-LABEL: @test3
52; CHECK: gc.statepoint
53; CHECK-NEXT: load i8, i8 addrspace(1)* @G
54entry:
55  call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
56  %res = load i8, i8 addrspace(1)* @G, align 1
57  ret i8 %res
58}
59
60; Even for source languages without constant references, we can
61; see constants can show up along paths where the value is dead.
62; This is particular relevant when computing bases of PHIs.
63define i8 addrspace(1)* @test4(i8 addrspace(1)* %p) gc "statepoint-example" {
64; CHECK-LABEL: @test4
65entry:
66  %is_null = icmp eq i8 addrspace(1)* %p, null
67  br i1 %is_null, label %split, label %join
68
69split:
70  call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
71  %arg_value_addr.i = getelementptr inbounds i8, i8 addrspace(1)* %p, i64 8
72  %arg_value_addr_casted.i = bitcast i8 addrspace(1)* %arg_value_addr.i to i8 addrspace(1)* addrspace(1)*
73  br label %join
74
75join:
76; CHECK-LABEL: join
77; CHECK: %addr2.base =
78  %addr2 = phi i8 addrspace(1)* addrspace(1)* [ %arg_value_addr_casted.i, %split ], [ inttoptr (i64 8 to i8 addrspace(1)* addrspace(1)*), %entry ]
79  ;; NOTE: This particular example can be jump-threaded, but in general,
80  ;; we can't, and have to deal with the resulting IR.
81  br i1 %is_null, label %early-exit, label %use
82
83early-exit:
84  ret i8 addrspace(1)* null
85
86use:
87; CHECK-LABEL: use:
88; CHECK: gc.statepoint
89; CHECK: gc.relocate
90  call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 0)
91  %res = load i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* %addr2, align 1
92  ret i8 addrspace(1)* %res
93}
94
95
96